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WILLIAM nDsoN, or.BosTonnAssAonUsnrTs Assiettes To n. `n. Asnl onori?, or SAME PLACE.

Letters Patent No. 97 ,489, dated December 7, 1869.

mnovnmnn'r IN nLnvAToRs.

The Schedule referred to in these Lettera Patent and making part of the same To all whom it may concern.-

Be it known that I, WILLIAM EDsoX, of Boston,

, in the county of Suffolk, and State of Massachusetts,

have'invented certain new and useful Improvements in Elevators for Hotelsstores, Soc.; and I hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings', making part of this specification and to the letters of reference markedl thereon, like letters indicating like 'parts wherever they occur.,

i l To ena-ble others skilled in the art to construct and use my invention, I will proceedcto describe it.

To the inner face of each of the posts A B is 'se-f cured a vertical shaft, I, ,in such a manner as to permit .the shafts to freely rotate.

Uponthese shafts I are secured a series of bosses or screws, R, of a diameter of six inches or more, theyy being placed at uniform intervals or distances apart, i and firmly secured.

The object of making the shafts and bosses thus, is, that it is unich cheaper than to take a shaft of the necessary size, andcut a screw in it its whole length;

and by making the bosses of so much greater diameter than the shaft, it affords an opportunity to attach pedestal-boxes or bearings to the posts A, for the sup port of 4the shafts I at frequent intervals between the bosses R, thus afibrding anydesired number of supporting-points for the shafts, and enabling me to fuse smaller shafts, and keep them rigid, and at the same time use bosses or screws of larger diameter, and con- -seqnently giving much larger' bearing-surfaces to the sorew-threads on the bosses, which, as will be seen hereinafter, support and move the load to be raised or lowered. f'

I can construct a cage or platform, C, in any suitable manner, of such a width as, when complete, to `iill the space crosswise between the screw-shafts.

To the outer faces of the sides H of the cage, I

`iirmly secure a plate, J, which reaches from top tobottom of the cage C, these plates J being formed with a semicircular groove, run ning vertically, on their outer faces, of a size corresponding to the diameter of the bosses R, and having a .screw-thread cut in these grooves to correspond with the thread on the bosses R.

The bosses I make usually about a foot' in length;

and the plates J should be'ot` such a length that when the cage is placed in position, the' plates will bear on one or more ofthe bosses at ell times. It is obvious, that it" desired, they may be arranged to bear on more of the bosses, and, where they are intended to raise heavy weights, this may be desirable.

It will readily be perceived that an elevator, constructed on this plan, can he nuule to raise a very heavy weight, and, at the same time, by so arranging the driving-mechanism as to give to the shafts I -a rapid rotation, the cage can be raised or lowered with rapidity, when desired. f

Another great advantage of this plan is, that there is but little oi' no danger of the cage falling, as it will stand wherever stopped, unless the screw-threads be made with great pitch. y

When it is desired to use the elevator' forraisiug heavy weights, the screw should have less pitch; but where the weight to be raised is less, the pitch of the screws may be increased, and they may he made with double or treble threads, if desired.

Having thus described my invention,

' What I claim, is-l v 1. The shafts I, having a series of screws or bosses, It, arranged thereon, substantially as audfor the purpose described.

2. In combination' with the shafts I, having the bosses R secured thereon, the plates J, having the 'semicircular grooves, with screw-threads cut therein, said parts being arranged for joint operation, substantially as described.

IVILLIAM EDSON.

Witnesses:

R. N. Enea, Jos. R. Enson. 

